In the manufacture of tissue products such as facial tissue, bath tissue, and paper towels, efforts are continually directed toward making these products softer and bulkier. Efforts to increase bulk are particularly important for bath tissue and paper towels, where bulk contributes to the perceived absorbency and effectiveness of the product.
Bulk can also play an important role for other paper products as well. For example, considerable work has been done by others on curling cellulose fibers for incorporation into newsprint to alter the web properties. In some instances, depending upon the nature of the cellulose fibers, the bulk of the final product was improved. See "Curl Setting - A Process for Improving the Properties of High-Yield Pulps," M. C. Barbe, R. S. Seth, and D. H. Page, Pulp and Paper Can. 85, No. 3: T44-51 (1984).